Electric lamps



y 28, 1968 K. G. 1.. JANSSON ET AL 3,386,070

ELECTRIC LAMPS Filed NOV. 26, 1965 INVENTOR. KARL GUSTAV LUDVIG JANSSONBOB$ORAN HULTHEN ATTORNEY United States Patent 3,386,070 ELECTRIC LAMPSKarl Gustav Ludvig Jansson, Stockholm, and Bo Goran Hulthen, Alvsjo,Sweden, assignors to Lumalampan Aktiebolag, Stockholm, Sweden, acorporation of Sweden Filed Nov. 26, 1965, Ser. No. 509,860 Claimspriority, application Sweden, Dec. 11, 1964, 15,044/64 Claims. (Cl.33925) ABSTRACT OF THE DISCLOSURE A decorative electric lamp is providedwhich provides an integrated clamping arrangement for attachment toChristmas trees and the like and which includes socket and base portionsformed of only two readily and inexpensively molded interfitting pieceswhich have formed in them interlocking elements for holding the variousindividual pieces together so that only a single rivet or screw and boltis necessary for holding the entire lamp assembly together, and meansfor holding the electric lead in a gripping stress-relieving fashion.

This invention relates to electric lamps or fixtures for receivingelectric light bulbs, and, more particularly, to small lamps especiallyadapted to such uses as being afiixed to the branches of Christmas treesand the like in the decoration thereof.

Conventionally, even very simple such Christmas tree lights are made upof a number of separate pieces formed of different materials, each ofwhich must be assembled in more or less intricate fashion and in amanner resulting in a cost greater than desired. Obviously, thissituation is aggravated if the design of the lamp is to be more than asimple socket (e.g., an imiation candle or other decorative design) andif it is desired to add a clamping member for holding the lamp on a treebranch.

If, as conventionally, the electric contact with the base of the lightbulb is to be maintained through the threaded socket in which the bulbis received, the formation of the socket itself requires some sort ofcore forming member (as opposed to simple molding) for forming the metalthreaded portion, and some sort of insulation at the bottom thereof foraccommodating the bottom contact. Thus, not only the formation of theseparate parts, but also the assembly and interconnection thereof can bemore intricate or time-consuming than desired, especially with regard tothe small size of Christmas tree lights. Also, the necessity forinserting a number of different rivets or other fastening means forintegrating the several parts may shorten the life of the finisheddevice as being points of weakness which may give way as the lamps arehandled or strung on the tree or collected for storage from one seasonto the next.

According to this invention, however, there are provided small lamps foruse, singly or in strings, for decorating Christmas trees and the likeand which may be made in a variety of decorative configurations orappearances, while yet comprising a desirably small number of individualparts, each of which is readily made and assembled with simple tools orby actual molding without expensive cores, etc., to provide a device ofincreased mechanical and electrical strength and stability, whileincreasing the ease and economy of fabrication and assembly into thefinished articles. Being generally, but not necessarily, circular incross section, the base parts of lamps in accordance herewith are formedas pairs of interfitting semicylindrical pieces for simple interlockingconnection to hold therebetween and in rigid disposition the variouscontacts and clamps and other members with but, preferably, a singlerivet or bolt for the entire device. A further fea- 3,386,070 PatentedMay 28, 1968 "ice ture of these articles is provision for electricalcontact with the bulb base other than through the threaded sides of thebulb-received socket, thus eliminating the need for forming the entiresocket of copper or other metal with thread corrugation therein.

With the above and additional objects in view, this invention will nowbe described in more detail, and other objects and advantages thereofwill be apparent from the following description, the accompanyingdrawing, and the appended claims.

In the drawing:

FIG. 1 is an exploded perspective view of one illustrative embodiment ofa lamp embodying this invention and with the assembled disposition ofthe exploded parts being indicated by the various broken-line arrows;

FIG. 2 is a perspective view on a smaller scale show ing the embodimentof FIG. 1 (illustratively designed to simulate a candle and holdertherefor) in finally assembled condition to receive a light bulbthreaded into the top end thereof; and

FIG. 3 is a fragmentary view on a larger scale indicating part of theinterlocking mechanism between two of the members of FIG. 1.

Referring to the drawing, in which like reference characters refer tolike parts throughout the several views thereof, one illustrativeembodiment of a lamp or fixture embodying this invention is shown assimulating the appearance of a candle in a candle holder having a drippan around the lower portion thereofalthough, as will be understood, theparticular decorative appearance or configuration of lamps embodyingthis invention may be provided in a wide variety of different forms,while still utilizing the mechanical expedients herein described asproviding the desired simplification of manufacture and assembly of thisinvention. As indicated, the assembled arrangement comprises generallyan upstanding tube 10 simulating a candle and for receiving at the upperend thereof a conventional Christmas tree light bulb having theconventional threaded base thereon, a base portion 11 simulating acandle holder with a drip pan 12 therearound, and a clamping device 13for clamping the lamp onto a Christmas tree branch or any other desiredsupport.

Referring more particularly to the exploded view of FIG. 1 and thevarious parts indicated therein, the bulb receiving socket to beinserted within tube 10 is formed of two semi-cylindrical socket members15, 15', which may be conveniently molded of plastic such as apolycarbonate plastic. Each of the socket members is provided with aninternal threaded portion 16 to form, when the two socket members areassembled together in faceto-face relation, a threaded socket forreceiving the threaded base of the light bulb. Because the electricalcontacts for the light bulb are arranged herewith, as will be describedbelow, other than in the conventional way utilizing a threaded metalsleeve within the socket as one contact element, the socket members 15,15' can be entirely molded of plastic material, and the threadedportions 16 thereof are used merely to hold the light bulb in place andmay be formed Without the necessary precision to maintain electricalcontact with the bulb. Indeed, the threaded portions can even bediscontinuous if desired. Because the socket is formed bytwo-semi-cylindrical members 15, 15', each can 'be very simply molded inone step without the necessity of providing or removing cores as wouldbe the case with a conventional cylindrical Onepiece socket member.

In addition to threaded portions 16, the two socket members 15, 15' alsoare provided with slots 17 and 18 for accommodating and retaining,respectively, spring metal electrical contacts 19 and 20 disposed withinthe threaded socket formed when socket members 15, 15

are assembled in face-to-face arrangement, with contact 19 beingdisposed across the bottom of the socket for electrical contact with thebottom contact on the light bulb and with contact 20* being disposedalong threaded portion 16 for providing electrical contact with thethreaded side of the base of the light bulb. Preferably, one or moreteats 21 are provided on socket member 15 with correspondingindentations (not shown) on socket portion 15' for the positioning andalignment of socket members 15, 15' in assembled face-to-face relation.Also as indicated, electrical wires 25 and 26 are connected in knownmanner to the lower ends of spring contacts 19 and 20 protrudindownwardly from the bottom of the socket portion when socket members 15,15' are assembled together with contacts 19 and 2t) therebetween.

As will be understood from the foregoing, socket members 15, 15' areassembled together with contacts 19, 20 therebetween, and the entireassembly slid upwardly within candle tube 10 to a position adjacent theupper open end thereof. In the illustrated embodiment, as means forpositioning and retaining the socket assembly adjacent the upper end ofthe tube 10, internal projections 27 (only one of which is shown) areformed in tube 10 for interlocking engagement with correspondingrecesses or indentations 28 (only one of which is shown) in the outersurfaces of socket members 15, 15' to maintain the desired axialpositioning of the socket in tube 10. As means for preventing rotationof the socket assembly tube 10, axial splines or ridges 29 are providedon the inner surface of tube 10 for engagement with axial grooves orshoulders 30, 30' on the outer surfaces of socket members 15, 15'. Suchprojections and splines are readily molded directly with tube 10 if itis formed of plastic material and preferably a material such as apolypropylene plastic possessing some resiliency for assembling socketmembers 15, 15 with tube 10 as noted.

The base of the entire structure is formed of two generallysemi-cylindrical elements 11, 11, being, in the illustrative embodiment,made to simulate a candle holder. As with socket members 15, 15, basemembers 11, 11' are quite simply molded for easy assembly, preferablybeing formed from a chip-proof impact-resistant material such as asyrene plastic, and are held together in assembled face-to-face relationby a single rivet or other fastening means indicated at 35, insertedthrough holes 36, 36.

Formed in each of base elements 11, 11' are two pairs of semi-circularnotches 37 (corresponding notches in element 11' not being shown in thedrawing) for engaging, preferably in a tightly gripping manner,electrical wires 25 and 26 to provide a clamping or gripping forcesufiicient to relieve inevitable pulling stresses from the solderedconnection of wires 25 and 26 with electrical contacts 19 and 20. Alsoprovided in each of base elements 11, 11' is a pair of diametricallyopposed slots or recesses indicated at 38 (and not shown in element 11')for engaging teats or projections 39 at the lower end of candle tube 10,when base elements 11, 11 are assembled into face-to-face arrangementaround tube 10, thus retaining tube 10 against axial removal from baseelements 11, 11'. In the lower portions of each of base elements 11, 11are formed corresponding parts of a spherical recess (shown only inelement 11) to provide, when elements 11 and 11' are assembled together,a generally spherical socket of a ball-and-socket joint for receivingand retaining ball 46 on clamp member 13 (illustrated as a conventionalspring clamp) to retain the entire lamp assembly on the branch of aChristmas tree or other support.

As will be understood from the foregoing, the socket assembly includingsocket elements 15, 15 and contact members 19 and 20 is inserted, asexplained above, into candle tube 19 and retained therein as described,with lead wires 25 and 26 extending out the bottom of tube 10. Then baseelements 11, 11' are assembled together in face-to-face arrangementaround the bottom of tube 10 so as to grip lead wires 25 and 26 innotches 37, to engage teats 39 in slots 38, and to engage ball 46 insocket 45. In this manner, the entire assembly is retained together byfastening rivet 35, 35 to base elements 11, 11'.

There is also provided, at least in the embodiment illustrated here, adrip pan 12, primarily for decorative purposes but also in a mannerwhich conveniently hides the heads of rivet 35, 35 in a preferredalthough obviously not necessary manner. Thus, drip pan 12 is hereprovided as a ring of decorative metal such as brass, and including twodepending spring clips 50, 50', serving as means for both hiding thehead of rivet 35, 35 and for holding drip pan 12 in position. To thisend, a recess 51 is shown in the outer surface of base member 11, asimilar recess being formed in base member 11, to receive, respectively,s ring clips 50 and 50 on drip pan 12. As shown in more detail in FIG.3, recess '51 includes a wedge shaped block 52' for engaging spring clip50'. Thus, as drip pan 12 is forced downwardly over tube 10 to fitaround flanges 53, 53' at the top of base members 11, 11, spring clip 50will fit into recess 51' in base element 11, will be forced outwardly bywedge 52', and will snap back underneath wedge 52 to be retained tightlyin recess 51'. A similar operation occurs with spring clip 50 in thecorresponding recess (not shown) on the outer surface of base element11.

As will be understood from the foregoing, there is thus provided,according to this invention, clamp-on lamps for receiving electric bulbsand in which the socket and base portions are each formed of but tworeadily molded interfitting pieces. Similarly, the interlocking meansfor maintaining socket elements 15, 15' in position within tube 10 andthe interlocking means for maintaining tube 10 and clamp 13 assembledinto base 11 all involve merely molded arrangeemnts all held togetherwith but a single rivet to provide extremely advantageous simplicity ofmanufacture and assembly for enhanced economy and rigidity and longlife. The utilization of simple electrical spring contacts 19 and 20,instead of the conventional metal threaded socket, permits themanufacture of all parts out of cheap and durable plastic materials,while also permitting an arrangement for gripping lead-in wires 25 and26 in stress-relieving fashion to increase the life of the solderedconnection thereof with contacts 19 and 20.

Although the illustrated embodiment is indicated as simulating a candleand candle holder, it is apparent that a Wide variety of otherconfigurations and decorative forms can readily be utilized,particularly in view of the fact that the design of the invention herepermits completely free use of plastic materials, with the electricalcircuit being independent of the other mechanical arrangements, and,accordingly, an almost unlimited choice of molded decorative or designconfigurations without increasing necessarily either the small number ofindividual parts involved or the ease of assembly thereof from twosimilar halves to be assembled in face-to-face relation in interlockingmanner as disclosed. Similarly, as will be apparent from the foregoing,socket elements 15, 15' and the threaded portion 16 thereof can readilybe formed so as to receive and retain a light bulb having a bayonetconnection or other forms of connection, instead of the conventionalthreaded base, without otherwise changing the ease of manufacture andassembly ad vantages hereof.

While the articles herein disclosed form preferred embodiments of thisinvention, this invention is not limited to these precise articles, andchanges may be made therein without departing from the scope of thisinvention which is defined in the appended claims.

What is claimed is:

1. An electric lamp of the character described adapted for receiving anelectric light bulb and for decorative use in connection with decoratingChristmas trees and the like, which comprises in combination abulb-receiving socket assembly for receiving and mechanically engagingan electric light bulb with operative electrical contact and including apair of substantially identical interlocking socket-forming member forassembly into face-to-face relation to form said bulb-receiving socket,a decorative outer member including an axial tubular passage forreceiving said bulb-receiving socket assembly in interlockingengagement, a pair of substantially identical base members forinterlocking engagement in face-to-face arrangement, and fastening meansfor maintaining said pair of base members in assembled relation, saidpair of base members including means forming an interlocking engagementwith said outer member for retaining all parts of said lamp in assembleddisposition upon fastening of said fastening means.

2. An electric lamp as recited in claim 1 in which said socket membersand said axial tubular passage of said outer member include cooperatingmeans for fastening and retaining said bulb-receiving socket assemblyWithin said tubular passage means.

3. An electric lamp as recited in claim 1 in which said socket membersinclude formed means for mechanically engaging and retaining a bulb insaid bulb-receiving socket substantially independently of electricalcontacts with said bulb.

4. An electric lamp as recited in claim 1 in which said bulb-receivingsocket assembly includes means for maintaining electrical contact withan electric light bulb engaged in said socket assembly and substantiallyindependently of said means for engaging and mechanically retaining saidbulb in said socket assembly.

5. An electric lamp as recited in claim 1 including electrical contactmembers for maintaining said operative electrical contact with a lightbulb received therein, electric lead wires connected to said contactmembers and extending out through said base members, and interlockingmeans in said base members for gripping and holding said lead wiresagainst pulling stresses thereon.

6. An electric lamp as recited in claim 1 including clamping means forpositioning and fastening said electric lamp upon a support therefor andinterlocking means on said base members for engaging said clampingmeans.

7. An electric lamp as recited in claim 1 in which said outer member isformed to simulate a candle and said base members are formed to simulatea candle holder, which also includes a drip pan member and means forinterlocking engagement thereof around said outer member and said basemembers.

8. An electric lamp as recited in claim 1 in which said bulb-receivingsocket assembly includes means for engaging and retaining an electriclight bulb having a threaded base thereon.

9. An electric lamp as recited in claim 1 in which said bulb-receivingsocket assembly include means for engaging and retaining an electriclight bulb having a non-threaded base thereon.

10. An electric lamp as recited in claim 7 in which said drip pan memberincludes means for decoratively hiding said fastening means.

References Cited UNITED STATES PATENTS 1,677,412 7/1928 Smith 339-251,727,148 9/1929 White 339-480 3,219,966 9/1965 Murakami 339-208 XRFOREIGN PATENTS 767,333 1/1957 Great Britain.

0 MARVIN A. CHAMPION, Primary Examiner.

PATRICK A. CLIFFORD, Examiner.

